Amy Adams will play the rocker, Daniels tells THR ("Guess what? She can sing her ass off!") -- and after that, the director's aiming for "Miss Saigon" and a horror movie.

While Lee Daniels' The Butler was triumphing in its opening weekend, its director was riveted by old videos of JanisJoplin. "This is my next project for sure," he tells THR of the planned biopic that's been stalled for a decade, starring AmyAdams as the boozy blues singer. "I had no idea Janis Joplin was so smart -- intellectual, even. Look, some of the smartest people in the world have been drug addicts."

As for svelte, well-mannered Adams playing an out-of-control rocker: "Guess what? She can sing her ass off!" A rock biopic seems out of character for Daniels, but it appears he's steering himself into difficult-but-rewarding eclectic waters. "After Joplin, I'm hoping to get Miss Saigon off the ground. And then -- I want to make a horror movie!"